A tweet from the official Japanese Twitter page of Pokken Tournament has revealed that the game will be receiving an all new challenger on December 10.
— ポッ拳 公式アカウント (@pokken_official) December 1, 2015
Even without knowledge of the Japanese language, the picture features the main Pokemon characters who have been announced so far, with a giant question mark in the center. Alluding to challenge screen in the Super Smash Bros. games when a new playable character has challenged you, the tweet itself features a single date of December 10.
When translated, the tweet simply states that a new challenger will be approaching on the specified winter date. There is now silhouette to create a classic “Who’s that Pokemon?” type of scenario, so unfortunately players will have to wait until December to find out more.
Pokken Tournament will be released in Spring 2016 for the Wii U and is playable now in Japanese Arcades.